PTH and Hypocalcemia: In children this elevation is twice the normal value,2,4 and in a burned sheep model, fractional excretion of calcium is not different from sham-burned animals despite significantly lower blood calcium.14 Moreover, serum concentration of parathyroid hormone (PTH) in children is inappropriately low for the blood calcium levels,13 indicating that children with burns have not only hypocalcemia and hypercalciuria but hypoparathyroidism as well.